Producing Mixed Alcohols from Biomass

Matt BehringJen Swenton

Goals

• Provide an economically feasible alternative to oil

• Provide a sustainable energy source• Provide a use for municipal waste

materials• Provide a smaller “Carbon Footprint™”

than oil production

What are Mixalcs?

What are Mixalcs?

• Dr. Mark T. Holtzapple– Texas A&M University– Developed MixAlco Process

What are Mixalcs?

• Mixalcs are a mixture of short chain alcohols such as; ethanol, butanol, propanol, pentanol an hexanol

• A mix of heavier alcohols can use existing technology

What are Mixalcs?

How can Mixalcs be used?

• Mixalcs can be used as a “neat” fuel or blended in almost any proportion into gasoline

• Can even blend with heavier hydrocarbons to improve emissions

Fuel Energy Content (BTU/gallon)Gasoline 125,000

Mixed Alcohols 104,000Ethanol 84,300

Where do mixalcs come from?

• Wide variety of feedstocks– Sweet Sorghum, Energy Cane– Municipal waste materials– Anything that decomposes!

Why are mixalcs so great?

• Renewable• Cleaner than gasoline• Higher energy content than ethanol• Lower volatility than ethanol• Lower heat of vaporization than ethanol

Carbon Footprint™

• Gasoline produces 19.4 lbCO2/gal– This only includes combustion

• Mixalcs produce 14.6 lbCO2/gal– This only includes combustion

• Gasoline produces 20% more energy• ~17.5 lbCO2/gal

Business Plan

Strategy

• Start Slow – Allow supply and demand to adapt– First sell mixalcs as addative– Then sell mixalcs as a substitute for

gasoline– Finally expand at a rate agriculture can

keep up with

Logistics

• Ideal location: Agrarian rural location with plenty of livestock waste, access to oil infrastructure, and cheap real estate

• Western Kansas

Logistics

Logistics

Logistics

TCI

• 40 tonne unit was selected to do cost estimation

• Lang factors were used to scale the process to different capacities

Numbers from Holtzapple

TCI2 10

Code Item Qty Unit Cost Unit Cost(unceEquipment Cost(r Lang Factor Exp 2&10 Exp 160&800 Installed Cost Installed CostA-1 Biomass loader 1 50,000 50,000$ 50,000 4.28 0.57 0.57 38,800$ 97,105$ A-2 Lime screw conveyor 1 5,500 5,500$ 5,500 4.28 0.56 0.56 4,398$ 10,831$ A-3 Biomass/lime mixer 1 50,000 50,000$ 50,000 4.28 0.57 0.57 38,800$ 97,105$ A-4 Fermentor 4 537,474 537,474$ 2,149,896 4.28 0.67 1.00 1,236,435$ 3,634,804$ A-5 Saturator tank 1 20,000 20,000$ 20,000 4.28 0.57 0.57 15,520$ 38,842$ A-6 Air blower 1 3,000 3,000$ 3,000 4.28 0.59 0.59 2,193$ 5,667$ A-7 Carbon dioxide blower 1 4,000 4,000$ 4,000 4.28 0.59 0.59 2,923$ 7,556$ A-8 Circulating pump 4 18,000 18,000$ 72,000 4.28 0.33 0.33 114,666$ 195,028$ A-9 Heat exchanger 4 4,300 4,300$ 17,200 4.28 0.50 0.50 16,461$ 36,808$ B-1 Compressor 1 120,000 120,000$ 120,000 5.04 0.79 0.79 56,728$ 202,295$ B-2 Gas Turbine 1 280,000 280,000$ 280,000 5.04 0.79 0.79 132,366$ 472,021$ B-3 Steam Turbine 1 90,000 90,000$ 90,000 5.04 0.79 0.79 42,546$ 151,721$ B-4 Condenser 1 16,250 16,250$ 16,250 5.04 0.60 0.60 13,573$ 35,649$ B-5 Rankine Pump 1 1,330 1,330$ 1,330 5.04 0.33 0.33 2,494$ 4,242$ B-6 Heat Exchanger 1 75,000 75,000$ 75,000 5.04 0.60 0.60 62,643$ 164,534$ B-7 Evaporator 1 228,299 228,299$ 228,299 5.04 0.75 1.00 121,664$ 406,808$ B-8 Sensible Heat Exchanger 1 1 40,874 40,874$ 40,874 5.04 1.00 1.00 10,300$ 51,501$ B-9 Sensible Heat Exchanger 2 1 21,897 21,897$ 21,897 5.04 1.00 1.00 5,518$ 27,590$ B-10 Evaporator Pump 1 12,000 12,000$ 12,000 5.04 0.33 0.33 22,505$ 38,276$ B-11 Evaporator Turbine 1 12,000 12,000$ 12,000 5.04 0.33 0.33 22,505$ 38,276$ B-12 Lime Mixing Tank 1 9,000 9,000$ 9,000 5.04 0.57 0.57 8,224$ 20,583$ B-13 Solids Separator 1 40,000 40,000$ 40,000 5.04 0.67 0.67 27,089$ 79,636$ B-14 Lime Conveyor 1 10,000 10,000$ 10,000 5.04 0.67 0.67 6,772$ 19,909$ B-15 Noncondesible Stripper Column 1 14,000 14,000$ 14,000 5.04 0.62 0.62 11,013$ 29,873$ C-1 Reactive Distillation 1 42,000 42,000$ 42,000 5.04 0.62 0.62 33,040$ 89,620$ C-2 Reactive Distillation Reboiler 1 50,000 50,000$ 50,000 5.04 0.62 0.62 39,333$ 106,690$ C-3 Countercurrent Heat Exchanger 1 16,000 16,000$ 16,000 5.04 0.62 0.62 12,587$ 34,141$ C-4 Switching Distillation Column 1 46,000 46,000$ 46,000 5.04 0.62 0.62 36,187$ 98,155$ C-5 Reboiler Heat Exchanger 1 1 7,000 7,000$ 7,000 5.04 0.62 0.62 5,507$ 14,937$ C-6 Reboiler Heat Exchanger 2 1 7,000 7,000$ 7,000 5.04 0.62 0.62 5,507$ 14,937$ C-7 Reboiler Heat Exchanger 3 1 6,000 6,000$ 6,000 5.04 0.62 1.00 4,720$ 12,803$ C-8 Condenser 1 11,000 11,000$ 11,000 5.04 0.62 0.62 8,653$ 23,472$ C-9 Mixer 1 10,000 10,000$ 10,000 5.04 0.69 0.69 6,379$ 19,365$ C-10 Filter 1 100,000 100,000$ 100,000 5.04 0.69 0.69 63,785$ 193,646$ C-11 Filter Pump 1 6,000 6,000$ 6,000 5.04 0.33 0.33 11,252$ 19,138$ C-12 Evaporator 1 56,388 56,388$ 56,388 5.04 0.75 1.00 30,050$ 100,478$ C 13 C 1 40 000 40 000$ 40 000 5 04 0 79 0 79 18 909$ 67 432$

Equipment Costs for all sizes of Mixalc plants

Numbers from Holtzapple

Product Cost

• Product cost was heavily dependent on Raw Materials cost

• Biomass feedstock cost will be highly dependent on market conditions

• Used a 4% inflation rate to do future calculations

• Royalties to Holtzapple were assumed to be 3% of gross sales

Numbers from Holtzapple

Product CostPlant Consumptions

Cost per rate or quantity 2007

Plant Specifications Calculated values, $Capacity, MT sorghum/h: 40Capacity, gal mixed alcohols/ 45100000Fixed Capital Investment (FC 19671269Product Price $/gal 2.00Raw Materials1 Sorghum 320000 MT/yr $40.00 USD/MT $12,800,000.002 Hydrogen 9,039,012 kg/yr $0.81 USD/kg $7,321,600.003 Lime 32000 MT/yr $44.00 USD/MT $1,408,000.004 Inhibitor 53,333 kg/yr $6.00 USD/kg $320,000.00 Labor (table 6-14) 8000 work-hr/year $173.75 USD/hr op $1,390,000Utilities (table 6-14)Electricity 5.94E+05 kWh/yr $0.05 $/kWh $31,467790-kPa Steam 207680 MT/yr $6.00 $/MT $1,246,080Natural Gas 288320 GJ/yr $4.00 $/GJ $1,153,280Cooling Water 2.23E+07 m3/yr $0.05 $/m3 $1,004,400Solid Fuel -1.18E+06 GJ/yr $2.00 $/GJ ($2,368,000)Maintenance and repairs 0.04 of FCI 786850.76

Operating supplies 0.15of maintenance and repairs 118027.614

Laboratory charges 0.15 of labor $208,500.00Royalties (if not on lump-sum basis) 0.03

of mixed alcohol sales $2,706,000.00

Depreciation - calculated separately below Total variable production costs: $28,126,205.11Taxes (property) 0.03 of FCI 590138.07Financing (interest) 0 of FCI 0Insurance 0.007 of FCI 137698.883Rent 0 of FCI 0

Fixed charges (without depreciation): 727836.953

Plant overhead costs $2,308,323.37Administrative costs $208,500.00Distribution + marketing costs $577,080.84Research and Development $1,442,702.10 Total general expenses $4,536,606.31

Total product cost (w/o D) C: $33,390,648.37

Numbers from Holtzapple

Profitability

• All processes can be profitable at reasonable mixalc prices

• Even if oil prices come down, mixalcs can be competitive

Profitability

Return on InvestmentROI = profit/TCI = R-D-(R-dIf)*tROI 19

Rate of Return based on discounted cash flow

function 567,239,693.48$ i 0.08n 10

Net Present Worth

i 0.08NPW $262,741,732

Pay Out Time

Average Cash Flow $43,247,008i 0.08POT 0.814731856

function = sumCF(1+i)^(n-k) + 0.15FCI + (TCI-FCI)-TCI(1+i)^10

NPW = sum(CFk/((1+i)^k)+(CFn+Vs+Iw)/((1+i)^n)-TCI

POT = (FCI-0.15*FCI)+TCI*i*n/average cash flow annually

Profitability

Uncertainty

• An uncertainty of 30% was applied to all equipment prices, raw material prices, and product price

• @Risk was used to evaluate the variation in NPW at this uncertainty

• 30% uncertainty was chosen in order to cover all possible inaccuracies in pricing

Uncertainty Distribution for NPW for 2 Mt/h unit

M ean = -168052.7

X <=2500000099.9477%

X <=050.7289%

0

0.2

0.4

0.6

0.8

1

-40 -30 -20 -10 0 10 20 30 40

Values in Millions

Uncertainty Distribution for NPW for 40 Mt/h unit

M ean = 2.627434E+08

X <=03.0296%

X <=999999977.65100%

0

0.2

0.4

0.6

0.8

1

-0.4 -0.2 0 0.2 0.4 0.6 0.8 1

Values in Billions

Uncertainty

Distribution for NPW for 800 Mt/h unit

M ean = 5.662068E+09

X <=02.1719%

X <=20000000000100%

0

0.2

0.4

0.6

0.8

1

-10 -2.5 5 12.5 20

Values in Billions

Uncertainty

• Agricultural prices will vary with demand

• This process and other biofuelsprocesses will put huge demands on agricultural production

• The impact that the biofuels industry will have on the agricultural industry will affect prices and supply in the future

MixAlco™ Process

MixAlco™ Process

• Developed by Dr. Mark T. Holtzapple at Texas A&M University

• Converts biomass feedstocks into a mixture of light alcohols

MixAlco™ Process

From Holtzapple p.5

Advantages

• No enzymes• No pure cultures• Continuous• Highly adaptable• Has potential to recycle various waste

products

MixAlco™ Process

From Holtzapple p.5

Pretreatment Fermentation

• Feedstock of 80% sorghum foliage and 20% cattle manure

• Pretreat with lime, water, and methane inhibitor

• Pretreatment removes lignin• Add bacteria such as marine mesophilic

organisms• Bacteria digests 80% of solid biomass1

• ~.5g of total acids per gram of feed1

• 4 piles each having the volume of 43,000m3

Pretreatment Fermentation

From Holtzapple p.9

MixAlco™ Process

From Holtzapple p.5

Dewatering

• Vapor compression evaporation• Introduce long chain acid to acidify broth• Steam and lime used to remove non-

condensable gases and calcium carbonate• Water is evaporated to concentrate salt

solution

Dewatering

From Holtzapple p.14

MixAlco™ Process

From Holtzapple p.5

Acid Springing

• Converts salts into acids• Concentrated acids are blended with CO2

and low molecular weight amines• Removes calcium carbonate• Calcium carbonate is recycled into

pretreatment

Acid Springing

From Holtzapple p.16

MixAlco™ Process

From Holtzapple p.5

Hydrogenation

• Converts acids to alcohols• Concentrated acids are mixed with high

molecular weight alcohols to form esters• Esters are hydrogenated to form alcohol

product

Hydrogenation

From Holtzapple p.18

Summary

• Can be blended or used as a “neat”fuel

• Further study of biofuel industry impact on agriculture is needed

• Further study on yield of bacteria when digesting different biomass is needed

References

1. Agbogbo, Frank K., & Holtzapple, Mark T. (2006). Fixed-bed fermentation of rice straw and chicken manure using a mixed culture of marine mesophilicmicroorganisms. Bioresource Technology, 98, Retrieved February 16, 2007, from http://www.sciencedirect.com.

2. Holtzapple, Mark T. (2004). MixAlcoProcess: Biomass to Carboxylic Acids and Alcohols. Unpublished Manuscript. Viewed January 2007